Cleaning of indoor air using pulsed discharge plasma

The purpose of this work is to develop a high efficiency air cleaning system for air pollutants such as tobacco smoke found in indoor environments. The authors have investigated the basic characteristics in treating particulate matter and acetaldehyde (CH/sub 3/CHO) in a one-pass test using a pulse generator and a plasma-driven catalyst reactor, which are attachable to an air conditioner. In circulation tests, they measured the decrease in acetaldehyde concentration in a closed vessel where this reactor was placed. The removal efficiency of particulate matter and acetaldehyde in one-pass test (residence time of 10 msec) were 70% and 27%, respectively. In the circulation test, the concentration of particulate matter was decreased by 90% after 10 minutes operation and acetaldehyde concentration was decreased by 70% after 50 minutes. It is thought that the TiO/sub 2/ catalyst is excited by plasma-induced high energy particles (electrons, photons, metastable molecules), resulting in an enhancement of pollutant removal. These test results indicate that the combination of plasma with TiO/sub 2/ is a potential alternative in treating pollutants in environmental tobacco smoke (ETS).